1. Field of Invention
The present invention is generally related to shredders for destroying articles, such as documents, CDs, etc. More specifically, the present invention is related to shredders including a rotatable device for moving shredded materials in a shredder.
2. Description of Related Art
During operation of a shredder, paper or other articles are fed through the input opening or throat of the shredder to be destroyed. As shown in FIG. 1, when paper is fed through a throat 101 of shredder 100, the paper travels into a cutting assembly 102 where it is shredded into smaller particles. The particles then exit through an outlet 104 of housing 105, and accumulate inside waste bin 103. However, problems may develop at or near the outlet 104 of the shredder 100, which may affect proper operation of the shredder.
One problem which may develop during shredding of articles includes when shredded particles adhere to or near the cutting assembly 102 or outlet 104 of the shredder 100. Such a phenomenon of accumulated particles known as “bird nesting,” as indicated by element 120. The shredded particles may accumulate due to physical or electrostatic means, for example. Over time, bird nesting particles 120 that accumulate near outlet 104 can become lodged inside the cutting assembly 102 or outlet 104 and reduce the sheet capacity (i.e., the amount of articles to be received and shredded in the cutting assembly) of the machine. Thus, extra strain may be placed on the gears, bearings, and motor (not shown) associated with the cutting assembly, and may even damage the cutting assembly 102. It is therefore desirable to reduce bird nesting particles 120 in order to extend the life and efficiency of a shredder 100 and maintain proper operation. This problem occurs more often in cross-cutting shredders, because the small chips formed by cross-cutting are more likely to accumulate.
Additionally, after articles have been shredded and particles descend from the housing 105, a second problem may develop. As shredded particles collect inside the waste bin 103, the shredded particles tend to accumulate in a shape similar to a peak or mountain, sometimes also referred to as “crowning,” as indicated by element 130. An accumulation of crowing particles 130 is inefficient since the particles will quickly build up. The crowning particles 130 may then perhaps start pushing against the cutting assembly 102, possibly contributing to the accumulation of bird nesting particles 120. The crowning particles 130 may also falsely or prematurely trigger a bin full detection system before the waste bin 103 is completely full. User assistance may then be required to either empty the waste bin 103, remove shreds that have accumulated near the output opening or cutting assembly, or to even out the pile of particles by hand before continuing to shred. Such assistance may not only be time consuming, but also dangerous. It is therefore desirable for a shredder to have particles which accumulate evenly in the waste bin 103, particularly in shredders that utilize a bin full detection system.
Some prior art methods have attempted to develop devices to curb such problems. For example, U.S. Patent Application 2008/0041988 A1 describes a brush-off device that slides reciprocally along shafts of a cutter assembly in an axial direction. However, the prior art fails to provide a feature for cleaning an underside of the cutting assembly or outlet. Rather, the prior art functions below the shredder housing.
To prevent crowning, the prior art, such as U.S. Patent Applications 2007/029542 A1 and 2007/0295736 A1, describes shredders having containers or bins that are rocked to prevent build up of particles. U.S. Pat. No. 7,150,422 B2 provides a manual device for pressing paper downwardly in the bin. However, none of the prior art devices are designed to operate inside or with the shredder housing to clear particles caught in the cutter elements of the cutter assembly, as well as assist in preventing crowning in the bin.